Effect of hesitation sound phonetic quality on perception of language fluency

Abstract

Nonnative speech differs from native speech in various ways, including different pausing patterns. There are two types of pauses: filled and unfilled. Unfilled pauses are silent. During filled pauses, speakers make a sound. Different languages use different sounds for filled pauses; this is described as phonetic quality. English speakers use “uh” to hesitate. Spanish speakers use “eh” to hesitate. When the phonetic quality of a hesitation sound is consistent with the hesitation sound used by native speakers, the hesitation sound is “native.” A hesitation sound with phonetic quality inconsistent with a native speaker hesitation sound is “non-native.” Production studies show that proficiency and speech community influence whether second language speakers produce native or nonnative hesitation sounds. However, no study has investigated the perceptual consequences using nonnative versus native hesitation sounds. This study investigates the effect of hesitation sound phonetic quality on perception of language fluency by comparing fluency ratings of sentences with nonnative hesitation sounds to fluency ratings of sentences with native hesitation sounds. This research answers questions such as: Do listeners judge non-native speakers to be less fluent when speakers produce non-native hesitation sounds? Is it beneficial for L2 learners to use native hesitation sounds to achieve perceived fluency?